1. Field of the Invention
The present invention relates to an automatic transplanter. More specifically, the invention relates to a mechanism for transferring seedlings or plants from plant trays or flats ("trays" and "flats" are used interchangeably in the art and in the application) in which they have been grown or propagated onto a conveyor for delivering to means for effecting transplanting into a field.
2. Related Art
Related prior art transplanters have included indexing mechanisms that engage on the ends and sides of trays containing seedlings or which engage a single contact point on the back of such trays. Therefore, these previous transplanters require a mechanism for ejecting the seedlings from the trays that is separate from the indexing mechanism. An inherent disadvantage of these previous transplanters is the frequency of misalignment between the seedling ejection apparatus and the rows of seedlings in a particular tray. This misalignment results from variations in the center-to-center distance between rows of seedlings in a tray and the center-to-center distance between the last row of seedlings on one tray and the first row of seedlings on a second succeeding tray being fed into position for ejection of the seedlings. Previous transplanters have relied on gravity for the feeding of a second tray into contact with the indexing mechanism after a first tray has been completely emptied. Consequently, soil or foliage trapped between the two trays often causes significant misalignment of the seedling ejection mechanism with the rows of seedlings in the tray; such misalignment can result in a multitude of malfunctions, none of which are beneficial.
Previous transplanters have employed feed mechanisms which require the use of hard plastic trays rather than trays made from materials such as expanded polystyrene which is of insufficient strength to withstand the forces exerted by such feed mechanisms because of the relatively soft nature of the expanded polystyrene. However, expanded polystyrene trays are desirable to use because of their light weight and lower cost.